Hi

I have a few questions relating to slow freezing in a freezer. I would be very grateful if somebody could kindly answer them for me.

1. In freezer engineering 'freezer capacity' refers to the weight of items that can be frozen at normal speed over a certain time period. This is different from the volume of space a freezer can hold e.g. a freezer which can hold 100litres of product. Freezer capacity is where for example a freezer can freeze 2kg of food in 12 hours. Is this correct?

2. I am told that the rate of freezing of an item depends on freezer capacity and product load. If you increase the product load over its' capacity significantly this will lead to slow freezing of the products. Is this correct and why?

3. I am told that the temperature in the freezer does not determine the rate of freezing but rather the final equilibrium temperature the product will reach.
However the same person (who I can no longer find) also told me changing the temperature alone will cause slow freezing but on the condition that the capacity of the freezer is big. He said slow freezing can be achieved by increasing product load over capacity or capacity over load.
Greatly increasing capacity over load doesn't make sense can somebody explain why this would lead to slow freezing?
I was told that if you set the temp of a domestic freezer to -5c this will usually cause slow freezing. However why would this be the case if -5c is only the equilibrium temperature. Assume the freezer is set to -18c and the freezer passes -5c in 2 hours, then surely if you lower the temperature to -5c it will reach that equilibrium in 2 hours also? Therefore the rate of freezing wouldn't be affected, just the final temperature reached?
Or am I missing something here where the professor told me temperature will assure it(i.e. lowering the temp to -5c) only if the capacity of the freezer is very high?


4. If somebody leaves say meat in a freezer for 6 hours at -1c, and then increases and leaves for 6 hours at -2c, and then increases and leaves for 6 hours at -3c, am I correct in saying the freezer wouldn't have slowly frozen the food over a period of 18 hours?
Rather what will happen is that if the freezer when set to say -18c normally gets food to -3c in 3 hours, then it will bring the food to -1c in an hour(assuming) and then the remaining 5 hours is stationary. The same thing will then happen after the 6 hours when the temperature is increased to -2c. Is this the case in which case it doesn't matter if you leave the freezer for long periods at higher temperatures since the rate of freezing will be the same? Or am I wrong?

Thanks.